Methods for performing medical procedures using a surgical robot

ABSTRACT

Embodiments are directed to a medical robot system including a robot coupled to an end-effectuator element with the robot configured to control movement and positioning of the end-effectuator in relation to the patient. One embodiment is a method for removing bone with a robot system comprising: taking a two-dimensional slice through a computed tomography scan volume of target anatomy; placing a perimeter on a pathway to the target anatomy; and controlling a drill assembly with the robot system to remove bone along the pathway in the intersection of the perimeter and the two-dimensional slice.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 14/476,101 filed on Sep. 3, 2014, now U.S. Pat. No. 10,531,927, which is a continuation of U.S. application Ser. No. 14/475,998 filed on Sep. 3, 2014 (abandoned), which is a continuation-in-part of U.S. application Ser. No. 13/924,505, entitled “Surgical Robot Platform,” filed on Jun. 21, 2013, now U.S. Pat. No. 9,782,229, which claims priority to U.S. Application No. 61/800,527 filed on Mar. 15, 2013, and claims priority to U.S. Provisional Patent Application No. 61/662,702 filed on Jun. 21, 2012, all of which are incorporated herein by reference in their entireties for all purposes.

BACKGROUND

Embodiments are directed to a medical robot system. More particularly, embodiments are directed to a medical robot system including a robot coupled to an end-effectuator element with the robot configured to control movement and positioning of the end-effectuator in relation to the patient.

Various medical procedures require the precise localization of a three-dimensional position of a surgical instrument within the body in order to effect optimized treatment. For example, some surgical procedures to fuse vertebrae require that a surgeon drill multiple holes into the bone structure at specific locations. To achieve high levels of mechanical integrity in the fusing system, and to balance the forces created in the bone structure, it is necessary that the holes are drilled at the correct location. Vertebrae, like most bone structures, have complex shapes made up of non-planar curved surfaces making precise and perpendicular drilling difficult. Conventionally, a surgeon manually holds and positions a drill guide tube by using a guidance system to overlay the drill tube's position onto a three dimensional image of the bone structure. This manual process is both tedious and time consuming. The success of the surgery is largely dependent upon the dexterity of the surgeon who performs it.

Robotic systems have been employed to help reduce tedious and time consuming processes. Many of the current robots used in surgical applications are specifically intended for magnifying/steadying surgical movements or providing a template for milling the bone surface. However, these robots are suboptimal for drilling holes and other related tasks.

Consequently, there is a need for a robot system that minimizes human and robotic error while allowing fast and efficient surgical access. The ability to perform operations on a patient with a robot system and computer software will greatly diminish the adverse effects upon the patient. The application of the robot system and the techniques used with the robot system may enhance the overall surgical operation and the results of the operation.

SUMMARY

Embodiments are directed to a method for removing bone with a robot system. The method may comprise extracting a two-dimensional slice from a three-dimensional computed tomography scan of a vertebra. The method may further comprise defining a perimeter on a pathway through the vertebra. The method may further comprise controlling a drill assembly with the robot system to remove bone from the pathway in the intersection of the perimeter and the two-dimensional slice.

Additional embodiments are directed to a method for inserting a tubular element into a patient with a robot system. The method may comprise loading computed tomography scans on to the robot system. The method may further comprise programming a route for the tubular element to travel through the patient to a section of the vertebra on a display, wherein the display may manipulate the robot system. The method may further comprise controlling the tubular element with the robot system to guide the tubular element along the programmed route through the patient.

Additional embodiments are directed to a method for aligning vertebrae for a surgical procedure using a robot system. The method may comprise inserting a tubular element into a patient and next to a disc space between adjacent vertebral bodies. The method may comprise attaching the tubular element to an end-effectuator of the robot system. The method may further comprise controlling a vertebral alignment tool with the robot system to insert the vertebral alignment tool through the tubular element such that vertebral alignment tool is inserted between the adjacent vertebral bodies to distract the adjacent vertebral bodies.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

FIG. 1 illustrates a partial perspective view of a room in which a medical procedure is taking place by using a surgical robot;

FIG. 2 illustrates a perspective view of a surgical robot according to an embodiment of the invention;

FIG. 3 illustrates a perspective view of a robot system including a camera arm in accordance with one embodiment of the invention;

FIG. 4 illustrates a front-side perspective view of a robot system including a camera arm in a stored position in accordance with one embodiment of the invention;

FIG. 5 illustrates a rear-side perspective view of a robot system including a camera arm in a stored position in accordance with one embodiment of the invention;

FIG. 6 illustrates a side cross-sectional view of a bony structure and critical structure with a milling bit inside a cannula positioned adjacent to the bony structure in accordance with one embodiment of the invention;

FIG. 7 a illustrates a side cross-sectional view of a bony structure and a milling bit with a programmed perimeter in accordance with one embodiment of the invention;

FIG. 7 b illustrates a top end cross-sectional view of the same bony structure as FIG. 7 a with a programmed perimeter in accordance with one embodiment of the invention;

FIG. 8 a illustrates a side cross-sectional view of a bony structure with a 2D slice through the bony structure indicated in accordance with one embodiment of the invention;

FIG. 8 b illustrates a top end cross-sectional view of the 2D slice through the bony structure confined to the programmed perimeter in accordance with one embodiment of the invention;

FIG. 9 illustrates a side cross-sectional view of a bony structure with the milling bit extending out of a cannula removing bone in accordance with one embodiment of the invention;

FIG. 10 illustrates a side cross-sectional view of a bony structure with the milling bit extending out of a cannula and removing bone from around a critical structure in accordance with one embodiment of the invention;

FIG. 11 illustrates a computerized display used to program the route of tubular element by a robot system in accordance with one embodiment of the invention;

FIG. 12 illustrates a center tool held by an end-effectuator and positioned next to an intervertebral disc space in accordance with one embodiment of the invention;

FIG. 13 a illustrates the spacer being removed from the end-effectuator in accordance with one embodiment of the invention;

FIG. 13 b illustrates a first dilator being positioned over a center tool in accordance with one embodiment of the invention;

FIG. 13 c illustrates a second dilator being positioned over a previously positioned dilator in accordance with one embodiment of the invention;

FIG. 13 d illustrates a third dilator being positioned over a previously positioned dilator in accordance with one embodiment of the invention;

FIG. 13 e illustrates the removal of a center tool and other dilators, with the largest dilator remaining in the patient in accordance with one embodiment of the invention;

FIG. 14 illustrates a vertebral alignment tool with a working channel in accordance with one embodiment of the invention;

FIG. 15 illustrate a vertebral alignment tool positioned outside two vertebral bodies in accordance with one embodiment of the invention;

FIG. 16 illustrates a vertebral alignment tool inserted into an intervertebral disc space, thereby aligning two vertebral bodies in accordance with one embodiment of the invention;

FIG. 17 illustrates a view looking down a tubular element with a vertebral alignment tool positioned inside the tubular element in accordance with one embodiment of the invention;

FIG. 18 illustrate an axial anatomical view of a vertebra with a tubular element and inserted interbody device in accordance with one embodiment of the invention;

FIG. 19 illustrates an axial view of a vertebra with a tubular element and inserted interbody device with the distance and angle needed to correctly position the interbody device in accordance with one embodiment of the invention;

FIG. 20 illustrates a perspective view of a surgical robot according to an embodiment of the invention; and

FIG. 21 illustrates a perspective view of a surgical robot separated in two structures according to an embodiment of the invention.

DETAILED DESCRIPTION

In an embodiment, as illustrated in FIGS. 1-5 , a surgical robot system 1 is disclosed in a room 10 where a medical procedure is occurring. In some embodiments, surgical robot system 1 may comprise a surgical robot 15, a display means 29, and a housing 27 to enclose a robot arm 23, and an end-effectuator 30 coupled to robot arm 23 controlled by at least one motor (not illustrated). In some embodiments a display means 29 may be attached to surgical robot 15, whereas in other embodiments, a display means 29 may be detached from surgical robot 15, either within surgical room 10 or in a remote location. In some embodiments, end-effectuator 30 may comprise a surgical instrument 35. In other embodiments, end-effectuator 30 may be coupled to surgical instrument 35. As used herein, the term “end-effectuator” is used interchangeably with the term “effectuator element.” In some embodiments, end-effectuator 30 may comprise any known structure for effecting the movement of surgical instrument 35 in a desired manner.

In some embodiments, prior to performance of an invasive procedure, a three-dimensional (“3D”) image scan may be taken of a desired surgical area of patient 18 and sent to a computer platform in communication with surgical robot 15. In some embodiments, a physician may then program a desired point of insertion and trajectory for surgical instrument 35 to reach a desired anatomical target within or upon the body of patient 18. In some embodiments, the desired point of insertion and trajectory may be planned on the 3D image scan, which in some embodiments, may be displayed on display means 29. In some embodiments, a physician may plan the trajectory and desired insertion point (if any) on a computed tomography scan (hereinafter referred to as “CT scan”) of patient 18. In some embodiments, the CT scan may be an isocentric C-arm type scan, an O-arm type scan, or intraoperative CT scan as is known in the art. However, in some embodiments, any known 3D image scan may be used in accordance with the embodiments of robot system 1 described herein.

In some embodiments, surgical robot system 1 may comprise a local positioning system (“LPS”) subassembly to track the position of surgical instrument 35. In some embodiments, robot system 1 includes at least one mounted camera 56. For example, FIG. 3 illustrates a perspective view of a robot system 1 including a camera arm 55 in accordance with one embodiment of the invention. In some embodiments, to overcome issues with line of sight, it is possible to mount cameras 56 for tracking patient 18 and robot 15 on an arm 50 extending from the robot. As shown in FIG. 3 , in some embodiments, arm 50 is coupled to a camera arm 55 via a joint 60, and arm 50 is coupled to robot system 1 via joint 65. In some embodiments, camera arm 55 may be positioned above a patient (for example, above patient 18 lying on a bed or stretcher as illustrated in FIG. 3 ). In this position, in some embodiments, it might be less likely for the surgeon to block the camera 56 when robot system 1 is in use (for example, during a surgery and/or patient examination). Further, in some embodiments, the joints 60, 65 may be used to sense the current position of the cameras 56 (i.e. the position of the camera arm 55). Moreover, in some embodiments, the exact position of end-effectuator 30 in the camera's 56 coordinate system may be calculated based on monitored counts on each robot axis, and in some embodiments, cameras 56 would therefore only have to collect data from tracked markers (not illustrated) on patient 18 to exactly calculate end-effectuator position relative to the anatomy.

Some embodiments include an arm 50 and camera arm 55 that may fold into a compact configuration for transportation of robot system 1. For example, FIG. 4 illustrates a front-side perspective view of a robot system including a camera arm 55 in a stored position, and FIG. 5 illustrates a rear-side perspective view of a robot system including a camera arm 55 in a stored position in accordance with one embodiment of the invention.

In some embodiments, surgical robot system 1 may comprise a control device 100. In some embodiments, the processor of control device 100 may be configured to perform time of flight calculations of radiofrequency signals emitted at the surgical instrument 35 or end-effectuator 30 and received by wall-mounted receivers 5. Further, in some embodiments, robot system 1 may be configured to provide a geometrical description of the location of at least one bony structure such as a vertebra with respect to an operative end of surgical instrument 35 or end-effectuator 30 that is utilized to perform or assist in performing an invasive procedure. In some further embodiments, the position of vertebrae, as well as the dimensional profile of surgical instrument 35 or effectuator element 30 may be displayed on a monitor (for example on display means 29). In one embodiment, end-effectuator 30 may be a tubular element 80 (for example a cannula 121, dilator 200, probe 190, or guide tube) that is positioned at a desired location with respect to, for example, patient's 18 spine to facilitate the performance of a spinal surgery. In some embodiments, tubular element 80 may be aligned with a z axis defined by a corresponding robot motor (not illustrated) or, for example, may be disposed at a selected angle relative to the z-axis. In either case, the processor of control device 100 (i.e. a computer) may be configured to account for the orientation of tubular element 80 and the position of vertebrae. In some embodiments, the memory of control device 100 (i.e. a computer) may store software for performing the calculations and/or analyses required to perform many of the surgical method steps set forth herein. The software or a computer program may be provided on a tangible computer readable storage media, which is non-transitory in nature.

Another embodiment of the disclosed surgical robot system 1 involves the utilization of a robot 15 that is capable of moving end-effectuator 30 along x-, y-, and z-axes. In this embodiment, an x-axis may be orthogonal to a y-axis and the z-axis, the y-axis may be orthogonal to the x-axis and the z-axis, and the z-axis may be orthogonal to x-axis and y-axis. In some embodiments, robot 15 may be configured to effect movement of end-effectuator 30 along one axis independently of the other axes. For example, in some embodiments, robot 15 may cause end-effectuator 30 to move a given distance along the x-axis without causing any significant movement of end-effectuator 30 along the y-axis or the z-axis.

In some further embodiments, end-effectuator 30 may be configured for selective rotation about one or more of the x-axis, y-axis, and z-axis (such that one or more of the Cardanic Euler Angles (e.g., roll, pitch, and/or yaw) associated with end-effectuator 30 may be selectively controlled). In some embodiments, during operation, end-effectuator 30 and/or surgical instrument 35 may be aligned with a selected orientation axis that may be selectively varied and monitored by an agent (i.e. control device 100) that may operate surgical robot system 1. In some embodiments, selective control of the axial rotation and orientation of end-effectuator 30 may permit performance of medical procedures with significantly improved accuracy compared to conventional robots that utilize, for example, a six degree of freedom robot arm 23 comprising only rotational axes.

In some embodiments, as illustrated in FIG. 1 , robot arm 23 may be positioned above the body of patient 18, with end-effectuator 30 selectively angled relative to the z-axis toward body of patient 18. In this aspect, in some embodiments, robotic surgical system 1 may comprise systems for stabilizing robotic arm 23, end-effectuator 30, and/or surgical instrument 35 at their respective positions in the event of power failure. In some embodiments, robotic arm 23, end-effectuator 30, and/or surgical instrument 35 may comprise a conventional worm-drive mechanism (not illustrated) coupled to robotic arm 23, configured to effect movement of robotic arm 23 along the z-axis. In some embodiments, the system for stabilizing robotic arm 23, end-effectuator 30, and/or surgical instrument 35 may comprise a counterbalance coupled to robotic arm 23. In another embodiment, the means for maintaining robotic arm 23, end-effectuator 30, and/or surgical instrument 35 may comprise a conventional brake mechanism (not illustrated) that is coupled to at least a portion of robotic arm 23, such as, for example, end-effectuator 30, and that is configured for activation in response to a loss of power or “power off” condition of surgical robot 15.

In some embodiments, control device 100 is also in communication with surgical robot 15. In some embodiments, a conventional processor (not illustrated) of control device 100 may be configured to effect movement of surgical robot 15 according to a preplanned trajectory selected prior to the procedure. For example, in some embodiments, controlling device 100 may use robotic guidance software (not illustrated) and robotic guidance data storage (not illustrated) to effect movement of surgical robot 15.

In some embodiments, the position of surgical instrument 35 may be dynamically updated so that surgical robot 15 is aware of the location of surgical instrument 35 at all times during the procedure. Consequently, in some embodiments, surgical robot 15 may move surgical instrument 35 to the desired position quickly, with minimal damage to patient 18, and without any further assistance from a surgeon (unless the surgeon so desires). In some further embodiments, surgical robot 15 may be configured to correct the path of surgical instrument 35 if surgical instrument 35 strays from the selected, preplanned trajectory.

In some embodiments, surgical robot 15 may be configured to permit stoppage, modification, and/or manual control of the movement of end-effectuator 30 and/or surgical instrument 35. Thus, in use, in some embodiments, an agent (e.g., surgeon, a physician or other user) that may operate robot system 1 has the option to stop, modify, or manually control the autonomous movement of end-effectuator 30 and/or surgical instrument 35. Further, in some embodiments, tolerance controls may be preprogrammed into surgical robot 15 and/or control device 100 (such that the movement of the end-effectuator 30 and/or surgical instrument 35 is adjusted in response to specified conditions being met). For example, in some embodiments, if surgical robot 15 cannot detect the position of surgical instrument 35 because of a malfunction in the LPS system, then surgical robot 15 may be configured to stop movement of end-effectuator 30 and/or surgical instrument 35. In some embodiments, if surgical robot 15 detects a resistance, such as a force resistance or a torque resistance above a tolerance level, then surgical robot 15 may be configured to stop movement of end-effectuator 30 and/or surgical instrument 35.

In some embodiments, control device 100, as further described herein, may be located within surgical robot 15, or, alternatively, in another location within surgical room 10 or in a remote location. In some embodiments, control device 100 may be positioned in operative communication with cameras 56, for tracking, and surgical robot 15.

In some further embodiments, surgical robot 15 may also be used with existing conventional guidance systems. Thus, alternative conventional guidance systems beyond those specifically disclosed herein are within the scope and spirit of the invention. For instance, a conventional optical tracking system (not illustrated) for tracking the location of the surgical device, or a commercially available infrared optical tracking system (not illustrated), such as Optotrak® (Optotrak® is a registered trademark of Northern Digital Inc. Northern Digital, Waterloo, Ontario, Mayada), may be used to track patient's 18 movement and robot's base 25 location and/or intermediate axis location, and used with surgical robot system 1. In some embodiments in which surgical robot system 1 comprises a conventional infrared or visible light optical tracking system (not illustrated), surgical robot system 1 may comprise conventional optical markers attached to selected locations on end-effectuator 30 and/or surgical instrument 35 that are configured to emit or reflect light. In some embodiments, the light emitted from and/or reflected by the markers may be read by cameras 56 and/or optical sensors and the location of the object may be calculated through triangulation methods (such as stereo-photogrammetry).

Illustrated in FIG. 2 , it is seen that, in some embodiments, surgical robot 15 may comprise a base 25 connected to wheels 31. The size and mobility of these embodiments may enable the surgical robot to be readily moved from patient to patient and room to room as desired. As shown, in some embodiments, surgical robot 15 may further comprise a case 40 that is slidably attached to base 25 such that case 40 may slide up and down along the z-axis substantially perpendicular to the surface on which base 25 sits. In some embodiments, surgical robot 15 may include a display means 29, and a housing 27 which contains robot arm 23.

As described earlier, end-effectuator 30 may comprise a surgical instrument 35, whereas in other embodiments, end-effectuator 30 may be coupled to surgical instrument 35. In some embodiments, arm 23 may be connected to end-effectuator 30, with surgical instrument 35 being removably attached to end-effectuator 30.

In some embodiments, robot system 1 may be used in common spinal surgery procedures such as Transforaminal Lumbar Interbody Fixation (“TLIF”), Posterior Lumbar Interbody Fixation (“PLIF”), Lateral Lumbar Interbody Fixation (“LLIF”), laminectomy or foraminotomy procedures. Robot system 1 may be used in any of the above mentioned approaches where bone removal may be needed. Specifically, robot system 1 may be able to target selected areas of bone for milling. Robot system 1 may further be registered to patient 18. In some embodiments, the means for registering may comprise radio-opaque fiducial markers and optical tracking markers rigidly attached to a patient-mounted fixture. Locations of fixture's fiducial markers on the 3D image may be related to tracked locations of the fixture's optical tracking markers to co-register camera 56 and medical image coordinate systems. In still further embodiments, cameras 56 may be used for tracking the location of the end-effectuator 30 or surgical instrument 35 in relation to the patient. Cameras 56 that may be used are to be similar to those used by the StealthStation® S7®, StealthStation i7™, or StealthStation iNav®, which track light-emitting or reflective markers using stereophotogrammetry. (StealthStation® S7®, StealthStation i7™, or StealthStation iNav® are registered trademarks of Medtronic, Inc.) Cameras 56 may be located on camera arm 55, see FIG. 2 , or stationed around patient 18. Once registered to patient 18, robot system 1 may very accurately gauge its end-effectuator's 30 location relative to any layer of bone viewable on a CT.

Embodiments of spine surgery techniques may include creating an access channel between two vertebral bodies or through bone. FIG. 6 illustrates a cannula assembly 120 that may be used to create an access channel through the tissue of patient 18 to target anatomy in accordance with one embodiment of robot system 1. In the illustrated embodiment, the cannula assembly 120 comprises a cannula 121 configured to allow passage of various instruments and materials through the pathway to target anatomy. The cannula may have an inside diameter just large enough to pass a drill bit or needle, or an inside diameter large enough to pass implants such as interbody grafts used in TLIF, PLIF, or LLIF. Cannula 121 may have a proximal end 122 and a distal end 123. Cannula assembly 120 further may include a drill assembly which may be removed from cannula 121. As illustrated in FIG. 6 , drill shaft 151 may be positioned in cannula 121 with milling bit 160 positioned at distal end 123. Drill assembly (not pictured) may further comprise a motor, a body, and parts known to one of ordinary skill in the art. In an embodiment, cannula assembly 120 may further comprise a handle (not illustrated) disposed on the proximal end 122 of cannula 121. In an embodiment, cannula assembly 120 may be a trocar-tipped cannula. By way of example, cannula assembly 120 may be a diamond, scoop, bevel, or trocar tipped cannula.

To create an access channel, the surgeon, for example, may make an incision in the back of patient 18. Distal end 123 of cannula 121 may be inserted into the incision. The surgeon may then apply longitudinal force to cannula assembly 120 while rotating the handle to advance cannula 121 through the soft tissue of patient 18 and cause distal end 123 to abut or penetrate into a bony structure. In an embodiment, cannula 121 may be inserted into the vertebral body through a pedicle (not illustrated). Once cannula 121 has been inserted to the necessary depth, the handle may be removed, leaving cannula 121. In this manner, cannula 121 may provide an access channel into the target site.

In a similar method, to form an access channel, the surgeon may make an incision in the back of patient 18. Proximal end 122 of cannula 121 may be attached to robot system 1 by way of end-effectuator 30. As described above, CT scans of patient 18 may be loaded to control device 100. Once loaded, control device 100 may register robot system 1, end-effectuator 30, CT scans of patient 18, and the current position of patient 18 on control device 100. Once registration on control device 100 is complete, the surgeon may program robot system 1 to align cannula 121 to a desired trajectory line 400 through patient 18 to a target site. As illustrated in FIG. 11 , the surgeon may designate a trajectory line 400 on control device 100, using display means 29, to reach the interbody space between two vertebral bodies. The robot system 1 may then control the cannula 121 to place the cannula 121 into patient 18 along the programmed trajectory. The surgeon may then insert a probe (not illustrated) through cannula 121 to monitor nerve activity. If adjustments to the trajectory are needed the surgeon may alter trajectory line 400 on control device 100 to an alternate position by means of control device 100, through an interface on display means 29. Robot system 1 may then immediately shift trajectory line 400 along new trajectory line 400. Control device 100 may be enabled to automatically shift trajectory line 400 away from neural activity, as provided by the probe, which may have reached a critical threshold. This automatic shift may allow tubular element 80 to reach the intervertebral disc space with a greater ability of avoiding nerves and causing nerve damage.

While cannula assembly 120 may be suited for creating an access channel to vertebral bodies or intervertebral disc spaces in all regions of the vertebral column, cannula assembly 120 may be particularly suited for access in the middle and lower areas of the thoracic region. If access is desired from the middle of the thoracic region and above, a device having a tapered cannula (not illustrated) may be used. While the tapered cannula may be particularly suited for accessing the middle of the thoracic region and above, it should be understood that the tapered cannula may also be used to create an access channel to vertebral bodies in all regions of the vertebral column.

After cannula 121 has been inserted and correctly positioned inside the body of patient 18, a drill assembly 500 may be inserted into cannula 121. The drill assembly 500 may comprise drill shaft 151, milling bit 160, and may further comprise a motor, a body, and parts known to one of ordinary skill in the art. Drill assembly 500 may attach to end-effectuator 30 by any suitable means. Furthermore, drill assembly 500 may be attached to end-effectuator 30 before insertion of cannula 121 or after insertion of cannula 121 into patient 18. As illustrated in FIGS. 7 a and 7 b , a surgeon may use control device 100 to define a perimeter 110 around an area within which the surgeon may desire to remove some bone with drill assembly 500. Perimeter 110 may be of any suitable shape or design the surgeon chooses. Without limitation, a suitable perimeter shape may be round, square, rectangular, any surgeon hand drawn enclosure, or any combination thereof. In one embodiment, perimeter may match the circular shape of the outer diameter of the cannula. As illustrated in FIG. 7 a , a side view of the bony structure illustrates the outer edges of perimeter 110. An end-on view, as illustrated in FIG. 7 b , illustrates the area of perimeter 110 in which milling bit 160 may operate. Uploading perimeter 110 into control device 100 may instruct end-effectuator 30 to prevent milling bit 160 from moving outside perimeter 110.

After perimeter 110 is loaded, control device 100 may then proceed to remove bone. By way of example, the control device 100 of the robot system 1 may control the drill assembly 500 for bone removal. In some embodiments, the control device 100 may turn on the drill assembly 500. Turning “on” the drill assembly may rotate milling bit 160 at about 500 to about 30,000 RPM, for example. Before removing bone, control device 100 may assess the demarcation between bone and soft tissue on a 2D reformatted slice (reslice) of uploaded CT volume of the anatomy inside patient 18. As illustrated in FIGS. 8 a and 8 b , reslice plane 170 may be perpendicular to the approach pathway but could alternately be perpendicular to the axis of the drill shaft 151, the axis of the cannula 121, or any suitable axis. Surgeon may instruct control device 100 to iteratively move reslice plane 170 distally down the axis of approach and distal to milling bit 160 before milling bit 160 advances. Control device 100 may display an image of reslice plane 170 as it advances. As illustrated in FIG. 8 , the surgeon may halt advancement and display of the reslice plane 170 at a position where the first bone is to be encountered. Control device 100 may be used to monitor exact location of drill bit 160 relative to the anatomy while surgeon advances cannula 121 to a known position relative to reslice plane 170 and drill bit 160. In one embodiment, this known position may be proximal to the reslice plane by the head depth of the drill bit 160. As illustrated in FIG. 8 b , an end-on view illustrates the cross section of reslice plane 170 and perimeter 110. The area in white is bone that may be removed by milling bit 160 and the area in black is soft tissue. In one embodiment, grayscale thresholding may be used to automatically assess and delineate white from black regions, providing data to control device 100 to automatically set boundaries for allowing or preventing drilling in different regions in this plane and bounded by perimeter 110. In another embodiment, the surgeon uses a software interface to manually mark bone and soft tissue areas on reslice plane 170. In one embodiment, control device 100 may enable drill shaft's 151 position to be moved laterally while maintaining angular orientation. Control device 100 may also only allow the drill bit to advance distally past the cannula tip if it is in the region in white but not in the region in black. In another embodiment, control device 100 may enable rotation of drill shaft 151 and may have it coupled with translation so that milling bit 160 position stays in reslice plane 170. Control device 100, with perimeter 110, may prevent drilling in any region that is not bone and allow removal of bone that is present within the cross section of perimeter 110 and reslice plane 170. The milling bit 160 may be advanced to remove bone distal to the cannula 121. In one embodiment, to limit bone removal to a region that has been viewed on resliced CT, the milling bit 160 is advanced only until it reaches the reslice plane 170. As illustrated in FIG. 9 , because the milling bit diameter is larger than the drill shaft diameter, milling bit 160 may be advanced to remove bone lateral to cannula 121 by the distance from the outer edge of the drill shaft 151 to the outer edge of the milling bit 160. This feature may allow for milling bit 160 to remove enough bone for cannula 121 to advance through or past the bony structure after bone is removed from in front of the cannula's leading edge. After removal of bone between cannula tip and reslice plane 170, which may be assessed by recording the area removed manually or on control device 100 by monitoring the registered position of end-effectuator and path of the bit, the surgeon may manually advance the cannula 121 into vacated space 185. A new reslice plane 170 on the CT scan of patient 18 may then be assessed from the existing CT scan volume by control device 100. In other embodiments, robot system 1 may assess multiple reslice planes 170 of the CT scan of patient 18 at the same time. The use of multiple reslice planes 170 may “look ahead” of milling bit 160. Viewing sequential slices in the path ahead of the current cannula location may alert the surgeon to a critical structure 180 that would harm patient 18 if removed by milling bit 160. As illustrated on FIG. 9 , the milling bit 160, which is connected to end-effectuator 30, may be advanced into or past bony structures in advance of the cannula 121. The milling bit 160 may remove bone allowing the cannula 121 to be advanced into or past the bony structure. Without the bone structures to block it, the cannula 121 would be pushed past soft tissues, which were not drilled, pushing these tissues aside as commonly occurs with cannula insertion.

As illustrated in FIG. 10 , a reslice plane 170 may eventually reveal critical structure 180. Control device 100 may alert the surgeon to critical structure 180. A critical structure 180 may be, but is not limited to a nerve, blood vessel, tumor, fracture, muscle, tendon, or any combination thereof into which one of ordinary skill in the art would not want to drill. The surgeon may then create a second perimeter 115. Second perimeter 115 may be plotted around critical structure 180. Second perimeter 115 may be of any suitable shape or design the surgeon chooses. Without limitation, a suitable shape may be round, square, rectangular, any surgeon hand drawn enclosure, or any combination thereof. Second perimeter 115 may be loaded into control device 100. Control device 100 may then prevent milling bit 160 or cannula 121 from entering the area defined by second perimeter 115. This second perimeter may allow for milling bit 160 to continue removing bone from around critical structure 180 without harming critical structure 180. As illustrated in FIG. 10 , critical structure 180 may prevent cannula 121 from advancing farther into the patient. In this respect, the critical structure is treated differently than soft tissues appearing as black on the reslice plane—with the soft tissues, the surgeon continues to advance the cannula forward and pushes them aside whereas with a critical structure, cannula advancement must stop. Milling bit 160 may continue to remove bone farther into the bony structure by staying within the bounds of perimeter 110, outside of second perimeter 115.

In some embodiments, robot system 1 may be used during LLIF operations. Current technology requires an LLIF access portal to be established. Portal placement is normally accomplished by a surgeon who inserts a probe from a lateral approach and guides the probe toward the disc space, adjusting the path as needed to steer the probe away from nerves in the psoas muscle and exiting the spine. As illustrated in FIG. 12 , robot system 1 may be used to move or guide manual movement of a center tool 190 through patient 18 during a LLIF procedure. Further illustrated in FIG. 12 are end-effectuator 30, spacer 210, dilator 200, and trajectory line 400. End-effectuator 30 is attached to robot system 1 and may be used to guide center tool 190 or hold center tool 190 and dilators 200 in place. End-effectuator 30 may grasp center tool 190 or dilators 200 by way of spacer 210 or any other means known to one skilled in the art. Spacer 210 may be removed and replaced as necessary to properly attach center tool 190 or dilators 200 to end-effectuator 30. As described above, patient 18 and CT scan volume of patient 18 may be registered together through control device 100. The surgeon may then plot trajectory line 400 on control device 100 through display means 29, which may display key anatomical views generated from the CT scans. Robot system 1 may align trajectory line 400 based upon the surgeon's inputs. The surgeon may insert a probe (not illustrated) through center tool 190 to monitor nerve activity as center tool 190 is maneuvered through patient 18 by robot system 1. If an adjustment to trajectory line 400 of center tool 190 is required, the surgeon may re-plot trajectory line 400 to an alternate position on control device 100, through display means 29. Robot system 1 may immediately correct trajectory line 400 of center tool 190, based upon re-plotting of trajectory line 400. Furthermore, control device 100 may be programmed to automatically shift trajectory line 400 of center tool 190 away from areas where neural activity has reached a critical threshold as measured by the probe inserted in center tool 190. After placement of center tool 190 against an intervertebral disc space, dilators 200 may be used to expand the working space available to a surgeon.

As illustrated in FIGS. 13 a, 13 b, 13 c, 13 d, and 13 e , after center tool 190 has reached the intended intervertebral disc space, one or more dilators 200 a, 200 b, or 200 c may be maneuvered down the length of center tool 190 to the intervertebral disc space. Center tool 190 and dilators 200 may be held in position by spacer 210. Spacer 210 may align center tool 190 and dilators 200 to end-effectuator 30. As illustrated in FIG. 13 a , spacer 210 may be removed to allow for the insertion of dilators 200 a, 200 b, and 200 c. As illustrated in FIG. 13 a , center tool 190 may be positioned against the intervertebral disc space in patient 18 by end-effectuator 30. After center tool 190 has been positioned, spacer 210 may be removed for the insertion of dilators to increase the work space available to a surgeon. Illustrated in FIG. 13 b , dilator 200 a, which may have inside diameter slightly larger than outside diameter of center tool 190, may be placed around center tool 190 and moved down center tool 190 until adjacent to the intervertebral disc space in patient 18. FIG. 13 c illustrates the same process in FIG. 13 b with dilator 200 b being slightly larger and moved along dilator 200 a. FIG. 13 d illustrates the same process in FIG. 13 c with dilator 200 c being slightly larger and moved along dilator 200 b. These steps may be repeated multiple times as desired by the surgeon (additional steps may not be pictured). As illustrated in FIG. 13 e , after dilators 200 a, 200 b, and 200 c have been placed, center tool 190 and dilators 200 a and 200 b may be removed. This removal may leave dilator 200 c attached to end-effectuator 30, creating a working space for a surgeon to operate in.

FIG. 14 illustrates a vertebral alignment tool 250, which may be used after insertion of tubular element 80, in certain embodiments. Vertebral alignment tool 250 may be used to prepare the intervertebral disc space of patient 18 for further surgical operations. As illustrated in FIG. 14 , vertebral alignment tool 250 may comprise a body 251, a penetrating end 252, and a working channel 253. Body 251 may be of any suitable width to fit within tubular element 80. Body 251 may be any suitable length to traverse the length of tubular element 80 and have a sufficient amount of body 251 exposed outside tubular element 80 for robot system 1, through end-effectuator 30, or a surgeon to manipulate vertebral alignment tool 250 inside tubular element 80 for placement between vertebral body 600 and vertebral body 601, in disc space 602. Body 251 may be of any shape (i.e. square, rectangular, round, polyhedral, etc.) that may distract (i.e. separate vertebral body 600 and vertebral body 601) vertebral body 600 and vertebral body 601. Penetrating end 252 may be attached to body 251 at one end of body 251. Penetrating end 252 may comprise two individual projections which may have tapered ends that come to a point. Both projections may be of any desirable length or width so as to prevent interference with working channel 253. Working channel 253 may traverse the interior length of body 251. Working channel 253 may be of any shape (i.e. square, rectangular, round, polyhedral, etc.) desired by a surgeon. Furthermore, working channel 253 may allow for surgical tools to pass through body 251 and penetrating end 252 to enter the disc space for surgical operations.

FIGS. 15 and 16 illustrate body 251, which may be the width of tubular element 80 (i.e. cannula, dilator, or guide tube) used during the operation. As illustrated in FIG. 15 , angled end 252 is positioned between two adjacent vertebral bodies 600, 601, which may not be prepared for surgical operations. As illustrated in FIG. 16 , vertebral alignment tool 250 may be moved into disc space 602 between adjacent vertebral bodies 600, 601, distracting adjacent vertebral bodies 600, 601 for surgical operations. The pointed tip of penetrating end 252 penetrates through the soft tissue and annulus and into the disc space 602. The vertebral bodies 600, 601 may slide along the tapering of angled end 252, coming to rest upon body 251. With the vertebral body alignment tool 250, the surgeon may employ tools down working channel 253 of vertebral alignment tool 250 for surgical operations.

Illustrated in FIG. 17 is a view looking through working channel 253 of vertebral alignment tool 250 in accordance with some embodiments. The orientation of the vertebral bodies 600, 601 relative to tubular element 80 may be known, and therefore, it is possible to insert vertebral alignment tool 250 into the disc space in proper alignment with the vertebral bodies 600, 601 to allow entry between vertebral bodies 600, 601. A locking dial portal (not illustrated), may be used on the proximal end of end-effectuator 30, allowing robot system 1 to hold vertebral alignment tool 250 in place. The dial, (not illustrated), may move to a new radial position through end-effectuator 30 by control device 100. Through registration of the robot system 1 to CT image volume, as described earlier, and with additional spatial information from the position of the dial, exact orientation and position of the vertebral alignment tool 250 relative to the anatomy is known. Control device 100 may then insert or guide vertebral body tool 250 between two vertebral bodies 600, 601 using end-effectuator 30. Control device 100 may track the movement of the vertebral bodies 600, 601 and control the depth and movement of vertebral alignment tool 250 until the vertebral bodies 600, 601 may be in a parallel configuration. A drill assembly 500, with a depth stop (not illustrated), or other disc removal tool such as Kerrison or pituitary rongeurs may be safely inserted into the disc space 603, through working channel 253, between the vertebral bodies 600, 601 to remove disc material.

After the surgeon has completed the operation, control device 100 may remove vertebral alignment tool 250 using end-effectuator 30. Control device 100 may monitor the movement of the vertebral bodies and remove the vertebral alignment tool 250 in a manner that may not harm the vertebral bodies. Similarly, the surgeon may remove the end-effectuator 30 from vertebral alignment tool 250 and remove vertebral alignment tool 250 manually. This method may be employed to remove any cannula 121, dilators 200, or drill assembly safely from the patient 18, after surgery.

Knowing the exact orientation of the disc space, by registration of patient 18 to robot system 1 (as discussed above), it may be possible to insert an interbody device 260 through tubular element 80, as illustrated in FIG. 18 , during XLIF with much better knowledge and real-time feedback about the actual final positioning of the implant than is currently possible. As the interbody device 260 advances through tubular element 80 and into the disc space, a representation may be displayed on control device 100 through display means 29 with an axial view of the vertebral body 700, especially the disc space, and current location of the interbody device 260 overlaid, as illustrated in FIG. 18 .

Another method for keeping track of the orientation of interbody device 260 is the dialable portal (not illustrated) as described above in the method of inserting vertebral alignment tool 250 using end-effectuator 30 of robot system 1. Such a portal would enable the user to control the orientation of the interbody device 260 during insertion and with feedback to control device 100 about the portal's angular orientation, either automatic through a sensor or manually entered by surgeon or technician, the orientation of the interbody device may be continuously monitored. An insertion tool (not illustrated) may have a sliding mechanism, which may be attached to end-effectuator 30, to orient the tool as is dictated by the portal.

In FIG. 18 , the interbody device 260 is intentionally illustrated malpositioned to clarify the degrees of freedom for which adjustment may be needed to fully seat interbody device 260 in the desired resting position. A surgeon advancing interbody device 260 from the lateral approach, predominantly moving interbody device 260 from a left to right position, may manipulate interbody device 260 as required to fully seat interbody device 260 in the desired resting position. Additionally, a means for manipulating predominantly the anterior-posterior position of interbody device 260 and a means of manipulating the rotational orientation of interbody device 260 in the plane may be required. One method for achieving the desired insertion is for the surgeon to dial in the necessary anteroposterior offset and the necessary rotation offset in robot system 1 integrated with tubular element 80, then to focus on advancing interbody device 260 through tubular element 80 until the desired depth of insertion is achieved. It may be necessary to displace interbody device 260 by the linear and rotational offset after advancing interbody device 260 and the insertion tool (not illustrated) far enough that interbody device 260 is clear of the distal end of tubular element 80 but before detaching interbody device 260 from the insertion tool. The desired final insertion depth may be controlled by an adjustable stop on the proximal end of tubular element 80 or by the user stopping when the user visually identifies interbody device 260 is far enough inserted on control device 100 through display means 29. Similarly, the angulation and linear offset of the interbody device 260 may be imposed after robot system 1 detects that at least some portion of interbody device 260 is clear of the distal end of tubular element 80 or after the user visually see the interbody device 260 is far enough inserted, on control device 100 through display means 29, that the displacement may not cause interbody device 260 to collide with tubular element 80. Detection of position and setting of robot system 1 may be automatically or manually controlled. That is, control device 100 may provide a surgeon with the anteroposterior distance “d” and the rotation angle “α”, as illustrated in FIG. 19 , that are required to reach the target after the surgeon has completed planning of the desired final location of interbody device 260 on control device 100 through display means 29. Alternately, control device 100 may automatically detect the required offsets and send a signal through robot system 1 to end-effectuator 30 to adjust to the appropriate offset positions.

FIGS. 20 and 21 further illustrate embodiments of surgical robot system 1 that may be used for any surgical procedure described above. FIG. 20 illustrates surgical robot system 1 in a stowed position. In the stowed position, surgical robot system 1 may be maneuvered into any surgical room, storage room, or down any hallway. Robot system 1 may comprise of a base 25, a surgical robot 15, a support structure 28, a housing 27, a display means 29, and a robot arm 23. Robot system 1 may further comprise a plurality of arms 50, a joint 65, a joint 60, and a camera arm 55. Robot system 1 may be maneuvered using a plurality of wheels 31 which may attach to robot system 1 through a wheel base 26. Wheel base 26 may support robot system 1. As illustrated in FIG. 20 , a first structure 200 and a second structure 205 may be attached to form robot system 1. First structure 200 may comprise of a base 25, a surgical robot 15, a support structure 28, a housing 27, a display means 29, and a robot arm 23. The second structure 205 may further comprise a plurality of arms 50, a joint 60, a joint 65, a camera 56, and camera arm 55.

FIG. 21 illustrates an embodiment of surgical robot system 1 in a deployed state, wherein structures 200 and 205 are separated from each other. First structure 200 may comprise a base 25, a surgical robot 15, a support structure 28, a housing 27, a display means 29, and a robot arm 23. Support structure 28 may support display means 29, housing 27, and robot arm 23. An end effectuator 30 (not pictured) may attach to robot arm 23 by any suitable means. End effectuator 30 may attach by any suitable means to any surgical tools described above (i.e. a cannula or drill assembly). Robot arm 23, end effectuator 30, and any attached surgical tools may operate according to any above described disclosure. Support structure 28 may rotate 360 degrees along the y-axis in relation to surgical robot 15. Robot arm 23 may further rotate or maneuver along the y-axis and x-axis, in relation to housing 27. Surgical robot 15 may move laterally along the y-axis in relation to base 25.

A second structure 205, illustrated in FIG. 21 , may comprise a camera 56, a camera arm 55, a joint 60, a joint 65, a plurality of arms 50, a wheel base 26, and a plurality of wheels 31. Structure 205 may be positioned away from structure 200 by a surgeon in preparation for surgery. The surgeon my position structure 205 in any manner in relation to structure 200 to relay information from camera 56 to surgical robot 15. The second structure 205 may position camera 56 above a patient (not illustrated), or position camera 56 in any relation to the patient. Camera 56 may send information from second structure 205 to first structure 200. The information transmitted may be received by surgical robot 15 and transmitted to display means 29 for display.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims. 

What is claimed is:
 1. A method for removing bone with a robot system comprising: providing an end effectuator to which a drill has been attached; receiving a defined perimeter on a desired trajectory through the anatomy to be drilled; retrieving a slice plane from a 3-D CT image scan volume, the retrieved slice plane being a two-dimensional slice lateral to a longitudinal axis of the drill attached to the end effectuator and being near the distal end of the drill; and controlling the drill to remove bone from the desired trajectory in the intersection of the defined perimeter and the slice plane; continuously retrieve a slice plane distally down the desired trajectory; for each retrieved slice plane, performing the following steps: repositioning the end effectuator such that the each retrieved slice plane is near the distal end of the drill; and controlling the drill to remove bone from the desired trajectory in the intersection of the defined perimeter and the each retrieved slice plane, wherein the each retrieved slice plane is a reformatted slice of the 3-D CT image scan volume, and wherein every one of the each retrieved slice plane is the two-dimensional slice perpendicular to the desired trajectory.
 2. The method of claim 1, further comprising defining, by a user, a perimeter on a pathway through the anatomy.
 3. The method of claim 1, further comprising displaying, on a display device, the each retrieved slice plane as the end effectuator is repositioned.
 4. The method of claim 1, wherein the end effectuator includes a tube, further comprising inserting the drill through the end effectuator tube.
 5. The method of claim 1, under the control of the robot system, automatically demarcating drilling area and non-drilling soft tissue area in the intersection of the defined perimeter and the each retrieved slice plane.
 6. The method of claim 5, wherein the step of automatically demarcating includes demarcating using grayscale thresholding.
 7. The method of claim 5, wherein the step of drilling includes controlling the drill to drill only in the drilling area under the control of the robot system.
 8. The method of claim 1, under the control of the robot system, further comprising: automatically demarcating drilling area and non-drilling soft tissue area in the intersection of the defined perimeter and the each retrieved slice plane using gray scale thresholding; and wherein the step of drilling includes controlling the drill to drill only in the drilling area.
 9. The method of claim 1, further comprising: identifying a critical structure to avoid in the slice plane; and placing a second perimeter around the identified critical structure within the first parameter.
 10. The method of claim 9, controlling the drill to remove bone only within the second perimeter.
 11. A method for inserting a tubular element into a patient with a robot system comprising: loading a 3-D computed tomography scan volume onto a control device of the robot system, the robot system further including a tubular element through which a drill is received; programming a route for the tubular element to travel through the patient to a target anatomical location on a display, wherein the control device is configured to manipulate the tubular element; controlling the tubular element with the robot system to guide the tubular element along the programmed route through the patient, wherein the control device calculates a two-dimensional slice plane perpendicular to a longitudinal axis of the drill attached to the tubular element and iteratively recalculates a slice plane distally down the programmed route and distal to the tubular element as the tubular element is advanced, wherein each calculated slice plane is a two-dimensional slice perpendicular to the programmed route and to the longitudinal axis of the drill, and wherein each calculated slice plane is a reformatted slice of the 3-D computed tomography scan volume.
 12. The method of claim 11, further comprising altering by a surgeon the programmed route while the robot system is moving the tubular element through the patient.
 13. The method of claim 11, further comprising: continuously sensing neural activity through a neural sensing probe inserted into the tubular element; and automatically changing the programmed route based upon the neural activity sensed by the neural probe. 